Clinical trial classification

There are two main types of trials or studies

Interventional study.

Observational study.

Trials can fall into two broad categories: pragmatic clinical trials and explanatory trials.

A placebo-controlled trial is a type of clinical trial

clinicaltrials.gov

cochrane central register of controlled trials

International clinical trials registry platform —-

The reviewer needs to correlate the type of study selected, whether it be observational or interventional, with the possibility that it will answer the research question. The type of study indicates the level or quality of evidence and the accuracy of the information.

see Study Classification.